It does not surprise me if this is true. I have often thought that if I gave a bad review something like that could happen (not that I have a book on Amazon though…) and that is one of the primary reasons I only review things I like or at least attempt to find positives in the things I review.
Freelance reviewer T. Michael Murdock reamed Conduit 2 earlier this month on gaming blog Joystiq, giving the Wii shooter one star out of five. Within a day, several negative reviews sprang up on the Amazon.com listing for Murdocks book, The Dragon Ruby, which is linked in the writers Joystiq byline. Some of the reviews have since been deleted.